Role and deficiency symptoms of secondary nutrients in grape Calcium (Ca), Magnesium (Mg) and Sulfur (S) are also found at high levels in grapevine tissue and contribute to the functioning and structure of the vine. Essential plant nutrients play important role in metabolic activities of the plant. Hence, proper supply of nutrients is very much essential for better growth and yield of the grapevine.

Calcium (Ca) is sometimes considered a “low key” nutrient, but it carries a heavy load in plant growth. It is important to use chemical fertilizers judiciously to get higher yield without affecting soil health. Thus, it is important to have knowledge about the role and deficiency symptoms of different elements on grapevines . Therefore in this RLO you will learn the role and deficiency symptoms of secondary nutrients on grapes.

Objective After completing this lesson, you will be able to : Learn the role and deficiency symptoms of secondary nutrients like Ca, Mg and S in grapevines

Role of calcium Calcium is important in the assimilation of N and transport of carbohydrates and amino acids. Calcium plays an important role in the structural functions in the cellular membranes and walls throughout the entire plant. Calcium, an essential part of plant cell wall structure, provides for normal transport and retention of other elements as well as strength in the plant. It also helps to counteract the effect of alkali salts and organic acids within a plant. 

Role of calcium Adequate calcium produced berries firmer, with a better appearance, better resist handling and transport and have a lower incidence of physiological disturbance. The greatest demand for Ca occurs during the post-harvest flush and the initial development of the berries.

Role of Magnesium Role of sulphur Magnesium occurs in the chlorophyll molecule and in enzymes that induce the formation of amino acids for protein synthesis. Application of excess amounts of Ca and K decrease the uptake of Mg. It also participates in P transport within the plant. Role of sulphur Sulphur is the principal component of amino acids and vegetable proteins. It is an enzyme activator and participates in chlorophyll synthesis.

Deficiency symptoms of calcium Deficiency of calcium decreased vine vigour and yield Excess calcium reduced the growth of root, shoot and leaves

Deficiency symptoms of magnesium Young leaves become necrotic and mature leaves become chlorotic. Interveinal chlorosis followed by necrosis become apparent from the beginning of chlorosis The chlorotic spot spread rapidly all over the blade and inward to the primary vein leaving only the inner half of the primary and secondary veins bordered by a normal green colour

Deficiency symptoms of sulphur Very less work has been done on sulphur nutrition in India. It may be because natural unintentional supply of S from the soil organic matter and the use of S rich fertilizers. Sulphur deficiency drastically decreases protein content in grape

Deficiency symptoms of sulphur Symptoms may be similar to N deficiency and are most often found in sandy soils that are low in organic matter and receive moderate to heavy rainfall. Plant stems are stiff, thin, and woody Higher concentration of sulphur-dioxide in the atmosphere near brick and other industrial units burning coal has resulted in Black tip. Its deficiency leads to side scorching of leaves.